Hydraulic transmission mechanism



y 28, 1929. Y s. G. WINGQUIST 1,714,652

HYDRAULIC TRANSMISSION MECHANISM Filed July 9, 1926 4 Sheets-Sheet l May28, 1929. s. G. wlNGQursi' HYDRAULIC TRANSMISSION MECHANISM Filed July 9, 1926 4 Shegis-Sh'ei 2 INVENTOR 2 42 By Afiomeys,

ii rcf-a y 1929. s. G. WINGQUIST 1,714,652

HYDRAULIC TRANSMI SS ION MECHANI SM Filed July 9, 1926' 4 Sheet-She'et a l INVENTOR By A iiomeys,

May 28, 1929.. s. G. WINGQUIST HYDRAULIC TRANSMISSION MECHANISM 4' Sheets-Sheet 4 Filed July 9, 1926 VENTORT Patented May 28, 1929.

UNITED, STATES OFFICE.

svnn'eus'ru W'INGQUIST, oEedrrnnnoize, SWEDEN.

. HYDRAULIC'TRANSMISSION MECHANISM.

L Q. i Application filed July 9, 1926. Serial No. 121,366.

' Tlie invention relates to .a mechanism in which power is transmitted from a drivin shaft to a driven shaft at variable spee ratios through the medium of a fluid acted upon by pumps. The object of an improved multi-speed clutch and transmission mechanism of high mechanical efiiciency and in which the resistance to the flow of the fluid transmission medium is comparatively small.

Another object is to provide in a fluid transmission mechanlsm mechamcalcouphng means between the elements of one or more-of the pumps whereby therelative movements of such elements may be checked to render such pump or pumps inoperative.

A further object is to provide a transmis- -sion in which the driving ratios are automatically controlled in accordancewith the varying conditions of load and speed, wherebythe operator is enabled to control the application of power to a driven member and to secure transmission conditions of free engine, slipping clutch drive, positive hydraulic speed reduction, and direct drive by simply manipulating the engine throttle or other energy controller of the'prime'mover.

Further objects of the invention will be pointed out in the following description,

throughout which reference is had to the accompanying drawings, in which,

Figure 1 is a vertical axial cross-section of the complete transmission.

Fig. 2 is a transverse cross-section taken along line II-.-II of Fig. 1 atthe left hand edge of the receiving pump chamber, the view being 'taken from the left. 0

Fig; 3 is a transverse cross-section taken along the line-IIIIII of Fig. 1, the section shows the parts as they appear when viewed from the ,left, 7

Fig. 4 is a transverse cross-section taken along the line IVr-IV of Fig. 1, and shows .ni'sm' for controlling the friction clutch in two different positions, both sections being shown along'the line VIIVII of Fig. 6, and showsthis invention .is to provide the pilot valve in the position corresponding to that shown in Fig. I

Fig. 8 is a transverse cross-section taken along the line VIII-VIII of Fig.,,1, and 4 shows the by-pass valves in section as they appear viewed from the right. 4

Fig. 9 is an axial vertical fragmentary section of the transmission, showing a modified form of fluid-actuated frictionrclutch.

"Fig. 12 is a schematic diagram illustrating I the direction of forces actingupon the ele-" ments of a reverse drive-transmission constructed generally asshown in Figs. 1 to 8 inclusive, but in which the'cap'acity' of the pump connected to the stator exceeds the capacity of the pump connected to the driven rotor.

Fig. 13 is a similar diagram indicating the forces obtained by constructing the transmission with pumps having the relative capacitiesof those shown inFig l.

Fig. 14. is a dia rammatic illl sgation of a modified .form 0 transmission 'which a speed reduction ishad by applying power to the internal rotor instead of tothe casing.

Fig. 15 is a schematic, diagram indicating the'for'ces acting upon the parts of the-transmission of the modified type shown in Fig. 14.

Fig. 16 is a transverse cross-section of the roller ratchet device 8,;as viewed from the left in Figure 1'- i. i t Fig. 17, is a transverse section'through the flexible coupling 7, as viewed from the left inFigurel. g v

A transmission constructed according to the present invention is applicable to any duty wherein power is required to be transmitted at variable speeds from a drivingv to a driven member. The embodiment now to be de scribed, and representing the preferred form of the invention is particularly adapted for use in automobiles, trucks and the like emsource of power. lhe present device elimi- 'ploying an internal combustion engine as a nates the necessity for tllllSllillJhOCllfiIllCfil gearing automobile transmissions and also the usual clutch mechanism, together with 'the manual controlling means for both the gears and clutch. With'the exception of a manual control of some usual braking means forarresting the motion of the vehicle an automobile equipped with my transmlsslon. requires only a single .manual control, thls control being the usual engine throttle or accelerator pedal, as it commonly termed. By the simple regulation of the engine throttle the operator is able to smoothly accelerate the vehicle from a standstill up to maximumspeed, the transmission automatically instituting appropriatetransmission ratios to se-' cure the maximum performance from a given power application. It is not-necessary, as

in the usual case, to reduce the, power of the engine during any of the speed-changing. operations, because in the present device, except when adjusted for idle running, the engine is never disconnected from the load.

The diiferential pumping system whereby power is transmitted through the fluid medium is fully set forth in my United States Patents Nos, 1,603,179, granted October 12,

1926, and 1,599,626, granted September 14,

, 1926. Certain features of the automatic No. 727,689, filed July regulating mechanism hereinafter to be described are covered by my co-pending United States applications: I

- Serial No. 575,673, filed July 17,1922; Serial No. 621,577, filed Feb. 27, 1923; Serial 23, 1924; and my United States PatentNo. 1,610,405, granted December'14, 1926. The special form of pump abutments and fluid passages between the abutments 'ofadjoining pumps are covered by my United States application, Serial No. 103,036, filed April 19, 1926, and the floating packing rings employed in the present device are. the subject of my co-pending United States appli cation, Serial N 0. 688,247, filed January 24, 192 1. c 7

Thepres'ent transmission is distinguished particularly from known devices of this'type in that, while the pumps are of fixed capacity,

' no valvesare interposed between the delivery'.

and rece ving pumps to' effect changes in transmission ratio. The elimination of valve mechanism between the co-operating pumps has very greatly increased the mechanical efficiency of the transmission when operating in reduced speed by providing a practically ideal path for theexchange of-fluid bet-ween the pumps, such path being perfectly smooth,

free from sudden turns and of minimum length. As the transmission is preferably operated with a lubricatingoil as the powertransmitting medium, the friction between the relatively movable parts of the mechanism is very low. Thus, with the practical elimination ofmechanical and fiuid'resistance, the efliciencyof the device is relatively Referring first to Fig. 1, the transmission will now beparticularly described. In this formfche device comprises a driving rotor 1 connected to a source of power through'driving shaft 2. A" driven rotor 3 is mounted within the said driving rotor and is fixedly keyed to the driven shaft 4. A releasable stator 5 also within the driving rotor 1 is formed with a-sleeve extension 6 surrounding the driven shaft, which extension is connected through a flexible coupling 7 with one element of a roller ratchet 8, the other ele-. ment of which in turn is mounted on the stationary frame or casing surrounding and sup porting the transmission mechanism. The

ratchet device 8-is designed so as to permit the stator 5 to freely rotate in thediroction of the driving rotor 1, but to prevent rotation in the opposite direction; so that a force tend ing to oppositely rotate the stator 5 will cause,

' it to be checked by the automatic operation of the ratchet devicel Under such circumstances it. becomes a fixed member againstwhich fluid may; react in the transmission of, torque between the driving-anddriven members of the. transmission. The driven rotor 3 and the stator 5carry sets of radially movable vanes which co-operate with abutments and working surfaces of the annular frame 10 of the driving rotor to form respectively the delivery pump A and the receiving pump or motor B. The two'pumps are of a wellknown vane pump type and are alsofully described in my co-pending applications hereinbefore referred to. The pumps are preferably identical in construction except that the capacity of the receiving pump B in the present embodiment of the invention may be made approximately one-half'thatof the delivery pump A, this resultingina reduced speed transmission ratio of approximately .nent elements.

If, for example, a speed reduction of 3 to 1 is desired, the capacity of the delivery pump A should be 1.5 times ceiving pump. 7

In Fig. 2,-the receiving pump or motor B is shown as it would appear when viewed from the left in Fig, 1. The vanes 9 slide closely along the Working surfaces 10', and are drawn the capacity of the reradially inwards by cam grooves 11 acting,

on the vane rollers 12 so as to escape the abut; ments 13 carried by the driving rotor frame 10, which frame also carries the aforesaid working surfaces. The abutments which in the present case are diametrically opposed,

. are designed'to provide an effective fiuidseal -against the periphery of the cylindrical stator element'on which the vanes 9 are mounted. The delivery pump A is shown in crosssection in Fig. 3 as it appears when viewed from the left in Fig. 1, the vanes20, working surfaces 21 and abutments 22 being similar to those of the receiving pump above 41escribed. The relative movements of the parts being reversed, however, the abutments are situated at the opposite ends of the-working I surfaces. The rotation of the driving rotor frame carrying the working surfacesand abutments of both pumps as in a counterclockwise direction, as indicated by the-arrows in Figs. 2 and 3, the rotor being viewed from the left in Fig. 1. The abutments of the delivery pump being connected tothe driving shaft, advancejwith respect to the vanes 20, the movement of which is resisted by the load on the driven shaft. This causes fluid to be delivered from the. pump A through passage 23 to the receiving pump B.'

In said receiving pump the fluid reacts against the then stationary vanes 9 and does useful work by impellin'g the abutments 13 in a direction favoring the rotation of the driving rotor. The receiving pump B virtually acts as a booster motor, augmenting the torque of the driving rotor. This additional torque is transmltted to the driven shaft 4 by virtue of an increased fluid pressure acting on the vanes 20. carried by the driven rotor 3.

The course of the fluid circulated between pumps A and B will be made apparent by consideration of the diagram in Fig. 10. The

figure is not drawn to scale nor are the various parts accurately illustrated. Furthermore,

in the diagram all the automatic control fea'- tures have been eliminated. Parts corresponding to those in Figs. 1, 2 and 3 are correspondingly numbered; The purpose of the diagram is merely to show the ceurse of the fluid in its circulation between the pumps and the direction of rotation of the several parts.-

Power may be applied to the rotor 1 by means of a' belt acting on. the pulley surface a.. The

abut-ments 22 of the delivery pump and abutments 13. fof the receiving 'pump form part of the driving rotor 1. The driven rotor 3 carrying vanes 20 (only two of the six vanes being shownyls fixed to the driven shaft 4. The stator 5 carrying vanes 9 is prevented from rotating by a checking device 8'which acts on the stator sleeve extension 6. The conduits between the pressure chambers of the delivery pump A and receiving pump 13 are diagrammatically indicated as pipes 23. The suction or idle fluid chambers of the pumpsare in open commnnicationthrough ports leading into the annular fluid chamber which completely surrounds both pumps and forms part of the driving rotor. v The series pump tothe annular fluid chamber.

of small arrows. indicate the movement of fluid when pump A is delivering fluid to re- I cei ving'pump B, while the large arrows at the-ends of the transmission indicate the direction of movement of driving and driven, parts.

As the abutments 22 ofumpA are rotated with the driving rotor, uid will be ejected from pump A due to the fact that the rotation of the driven rotor 3 and vanes 20 is re.- sisted by the load on the driven shaft. The fluid entering-the pressure chamber of the receiving pump 'or motor B reacts against the stationary vanes 9'and builds up apressure,- which, exerted upon the abutments 13 of the driving rotor, results in the transfer of torque to such rotor. At the same time the faces of the abutments in pump A, which faces are not exposed to the driving fluid" pressure, are movlng away. from the vanes 1n, the suction chambers of the pump, thereby drawing in fluid from the annular fluid chamber formed in the driving rotor. The faces tween the vanes and abutmcnts of the receiving pump B will occur. In consequence, no fluid can circulate in the system. The fluid trapped in the pressure chambers of the pump A between the abutments on'the driving rotor and vanes on the driven rotor will effectually couple the driving and driven parts together so that they will rotate as a unit. By this method directdri've is achieved.

lVithoi1t any alteration in the device shown in Fig. 10, a. gearing up instead of a gearing down effect may be achieved by applying power to the shaft 4, the casing 1 which was formerly the drivingelemcnt now being the driven element. Under such conditions the flow of fluidwill be reversed, providing the arrow, the pump 13 becoming the delivery pump and causing fluidto flow under pressure to what is now the recei ving' pump A. If the transmission in'the former case gave a 2 to -1-speed reduction, 1t Wlll now, with the dr1v-,

ing and driven parts interchanged, give a 2 to 1 lncrease 1n the speed.

A reverse drive may also be had through a .shaft 4 is still rotated in the direction of the'- transmission similar to that indicated in Fig.

10 by increasing the size of pump B so that its capacity is greater thanthat of pumpA.

tion (opposite to the direction indicated by the arrows), the pump B. will deliver fluid under pressure to the pump A, which, under such. conditions, becomes a receiving pump, the abutments w13 advancing counter-clockwise towards the stationary vanes 9 forcing fluid through-conduit 23 to the pressure chamber of pump A. In spite of the fact that the abutments 22 are driven in a counter-clock wise direction, the vanes will be moved by the fluid entering the'pump A, which now acts as a receiving pump, in a clockwise direction because of the fact-that the capacity of pump 1 panded by a downward movement of the vane 20. I

B exceeds the capacity of pump A.

This will be clearly'understood if we assume for a moment that the two-pumps are made'of equal capacity.

Under such conditions a movement of-abutments 13 toward the stationary vanes 9 will displace exactly the amountot fluid, ,which, acting upon the A pump, will permitabutments 22 to move countor-clockwise with respect to vanes 20 without creating either pressure or suction, and in consequence, said vanes will remain stationary. If, however, as in the present case, the capacity of pump B exceeds the capacity of pump A, more fluidwill be. delivered to the pressure chamber of the latter pump than.

can be swallowed by the relative movement of the abutments and vanes occasioned by the counter-clockwise rotation of the abutments.

i In consequence of this, the excess fluid delivered to the A pump will cause a backward rotation of the driven element carrying vanes 20, and the rate of this backward rotation will be dependent upon the-relative capacie ties of the two pumps, it being possible to obtain any reverse speed reduction or speed in crease by varying the capacity of the A pump between that equal to the capacity of pump B and an extremely small capacity, which,

obviously, would give rise to very high reverse speeds.

The comparison of the forward and reverse drives which may be had by constructing the transmission either with the capacity of pump A or pump B respectively the larger, is simply illustrated in the diagrams shown in Figs. 12

and 13. In thelatter figure corresponding to the construction shown in Fig. 1 the driving elementl carrying the abutments 22 and i 13 of both pumps A and B, is shown as mov- 'ing downwards.- The driven element 3 carrying vane 20-also moves in the same direction,

but because. the abutment 13 of the receiving pump B is, by its downward movement en- 13 -is moved upwards, the driven element 3' will be propelled downwards because of the I fact that the upward movement of abutment 13 toward the stationary vane 9 causes a greater quantity of fluid to be ejected from pump B (now acting as a delivery pump) than can be swallowed by pump A? (new acting as a receiving pump or motor), unless the working chamber of the latter pump 13 ex- In both'Figs. 12 and 13, and in Fig. 15, which will presently be discussed, avalve 24% is interposed between the two pumps. This valve illustrates a means heretofore known for, efiectively coupling the driving and driven elements of the transmission together I for direct drive 'by trappin'g fluid in the chamber of the pump, the elements of which,

are interposed between the driving and driven members. of the transmission. Ac-

cording to the present inventlon, such valve has been eliminated, and instead the circu lationof fluid between the pumps is controlled pref-erably'by connecting the releas- -able stator 5 with'the element of the transmission with which itco-operates to form a' pump, so that relativemotion of the parts of such pump is prevented. Inthis manner the pump is just as efiectually eliminated as a factorin producing a flow of fluid in the system as if avalve, such as the valve 24,

were 'interposedbetween the pumps to stop circulation between them.

In Fig. 14 there is diagrammatically shown' the modified. form of transmission to which my co-pending United States application Se-f rial No. 588,657 previously referred to relates. This construction differs from that illustrated in Fig. 10 in that the fluid connection between the two pumps connects simthe casing 1' being the driven element and carrying abutments 13 and 22 of the two shaft 4 be rotated in a clockwise direction, thevanes 20' approach the driven abutments 22' by" the load, and fluid is thereby forced through conduits 23' to the working charm-- bers of the receiving pump B. The reaction of the fluid against the stationary vanes- 9f builds up a ll 'd pressure within the chamthe motion of the latter being resistedpumps A, B respectively. If the driving iso bers of the receiving pumpBQwhichproduces a thrust in a clockwise direction a ainst the I .abutments 13 which form part oft e driven rotor. Inthis form of device it will there-.

5 fore be observed that the casing '31 is urged in a-clockwise direction bytwo forces, one

being the fluid. pressure against the abut' ments 22' of the delivery pump, and the other being the fluid pressure against the abutments 1-3' of the receiving pump. lf,

for example, the areas of the abutments in both pumps are equal, the torque on the a driven element 1 'will be twice that applied to the driving shaitd' if the fluid is permitthe torque produced by the, prime mover and transmitted to vanes 20- is suficient to give rise to a certain fluid pressure, this pressure torque producing surfaces of the two sets of drivenabutments, which have together just Itwice the effective area of the driving vanes 20', will exactly double the torque delivered by the driven element.

In the modified form of transmission illustrated in Fig. 14, which I will hereinafter refer to asmy inverted drive, (the device in Fig. 10 being considered the normal drive),

the idle fluid returnthrough the outer casing 1'; requires no explanation, asvthe' annular fluid chamber completely surrounds both pumps, as heretofore described. The idle fluid exhausts from the pump B and is re- L turned: to the pump A, asindicated by the I.

fsmall arrows within the casing: The diagram in Fig. indicates the fluid flow and direction of iorcesacting upon the elements of the inverted drive above described. Power is applied to the rotor 3" carrying vanes in an upward direction.

If the pumps A, and B are functioning, the stator 5 carrying vanes 9'- will remain stationary, andfluid will be forced out of the capacity, a 2 to 1 speed reduction will be had. The greater the relative capacity of the pump B, the greater will be the speed reduction. 7

It will also be evident that if the driving and driven parts be interchanged, that is to say, if the part 1 be moved do'wnwardly, ,the part 3 becoming the driven member, will :move

downwardlyat a rate faster than thedrivingclement. The driving ratio of a transmisted to circulate between the two pump sys-I- tems, as above desc'ribed.- If, for example,

applied in the two pumps to the combineddriven parts. 7 If the two pumps are or equal sion of the inverted drive type may be determined by the'following equation:

-l)riving s1& fi M+D Driven speed T D V Where M=the volumetric capacity 'of the receiving pump B, and

D=the volumetric capacity of the delivery pump A;

The foregoing discussion of the principles involved in th e various forms of. my trans-.

mission device have been given primarily" to indicate that thepresent invention is applicable to a variety-of types or hydraulic transmissions and is in no way limited to the detailed construction illustrated in Fig. l,

for example. r

0n the contrary, my" invention is equally apphcable to any transmission employing one pump which is actuated by the difference in speed between a driving and a driven shaft and another pump in fluid communication therewith, which is actuated by the diflerence in speed betweena stationary elementfand either the driving or driven shaft. Instead of controlling the flow oi fluid betweensuch connected pumps by means "of a valve whereby to lock the fluid between the driving and driven elements so as tdproduce a direct drive, I provide means for mechanically connecting the stator to the element with which it otherwise normally co-operates, and there-" byeliminate from the system the capacityof one of thepumps. The stator, of course, is released atsuch times for free rotation with the said element. in this manner, what may be called the stator pump of the trans mission shown in Fig. 1 is no longeroperative,

and in consequence, no fluid will circulate between it and thepump interposed between the driving and driven shaitsto eflect a change in the transmission ratio.

Returning now to complete'thedescr iption of the preferred embodiment of the invention illustrated in Figs. 1 to ll inclusive,-we will considerthe assembly of the driving rotor 1, within which the two pumps Aand B are mounted, together with the automatic con:

trol means therefor. As previously ointed out, the; abutments and working sur aces ot the two vanerpumps are formed within the annular-driving rotor frame 10.. This frame is divided into-two compartments by pertition 30, through the central boreof which passes a'flanged sleeve 31 which serves as a journal for the left hand end ofthe driving rotor. Sleeve 31 is rigidly secured in the said partition but freely rotates about the driven shaft 4. which supports it. Within the two compartmentsformed in the rotor frame 10, the previously described vane pumps A and B are mounted, and the pump. chambers are'closed by the rugged end plates -32 and '33. The end plate 32 is provided quired to pass through it; Power is transmitted to the transmission through a flange 35 formed integrally with cover 34, the flange on the driving shaft 2' being bolted to the cover flange 35,,as shown, or coupled thereto by any suitable flexible coupling means. The lefthand end of the driving rotor is completed-by a clutch housing plate 36 and a comparatively light weight fluid-retaining apron 37 which latter completely surrounds the two pumps and automatic control mechanism therefor to the left of the end plate 32 above referred to. The annular driving rotor frame 10, together with the end plates 32, 33 and clutch housing plate 36, are rigidly fastened together so as to form a substantially unitary structure, by means of aplurality of lag-bolts 38 and 39. The right hand cover plate 34, ,and apron 37, which serves as the fluid-retaining means for the left hand .part of the'transmission, are flanged as shown in Fig. 1, the flanges thereof being securely fastened against the projecting rim of end plate 32 by means of clamping rings 40, which are secured in place by bolts 41.

The apron 37 is at its left end firmly clamped against the plate 36 by means 'of a locking ring 42 which is threaded on an annular hub-like projection 36- formed integrally with the clutchhousing plate 36. The said locking ring actually presses against the V annular floating packing device 43, which, in turn, forces apron 37 against plate 36.

The apron 37 above referred to provides a large and unobstructed annular idle fluid chamber around the working parts 'ofthe transmission whereby the idle fluid may be returned from the exhaust of the receiving pump B, to the suction or intake ports of pump A. This chamber also encloses the friction clutch and automatiocontrol devices in the left hand end of the driving rotor and is in open fluid communication. with such devices. Said chamberalso through ports 34" communicates directly'with the compartment. 34 in .which certain automatic valves are located, aswillhereinafter be more fully set forth.

e The entire transmission is surrounded by a stationary annular casing 51, which, where v the transmission is applied to an internal .combnstion engine, is preferably rigidly I, mounted upon the engine crankcase 52 orother part of the engine frame formed integrally therewith. bearing supporting plate 53 is rigidly clamped in the left hand end of casing 51. An annular reinforcing or backing member 53. is rigidly secured to supportin plate 53 and casing 51 by means of a plurality of bolts 54 which pass completely through these three elements, as shown in Fig; 1. Theannular reinforcing member 53' .is centrally recessed to receive the annular roller ratchet device 8 and to hold the outer element of thesame rigidly in position. The member 53' is at its right hand side interiorly threaded to receive a locking ring 53" which clamps the diaphragm of the floating.-

pa'slring device 43 firmly against a shoulder 53" pro3ect1ng inwardly around the bore of the annular reinforcing member 53'. The

- floating packing device 43 is in every respect except size, similar to the floating packing 63,

which will hereinafter be more fu'lly described, so.that no further description need here'be made of this element.

The bearing plate 53 has two important functions: One being to afford a support for the end bearing 55 of the driven shaft 4, and.

the otherto afford a suitable mounting for the roller ratchetdevice 8 through which the left hand element 56 of flexible coupling 7 connected to the releasable stator 5, is,

clutched or released from the stationary frame of the transmission in accordance with the direction of forces tending to rotate, or resist the rotation of, the stator 5 which forms the internal element of the receiving pump B. The roller ratchet device 8 is shown in transverse section in Fig. 16, as it appears viewed from the left in Fig. 1', and isof the usual construction. An outer annular ring 57, which 1s fastened to plate 53, has formed within it a plurality of roller recesses 58havinginclin'ed surfaces 59, between which, and the relatively movable element 56 of the ratchet device, rollers 60 are adapted'to effect a clutching action when the element 56 which is connected to the stator of pump B tends to rotate in a clockwise direction.

The flexible coupling 7 between the tubular extension 6 of stator 5, and the internal element 56 of the roller ratchet device 8, may be of any known construction. In Fig. 17

there is illustrated a suitable form of cou-v pling, which comprises two inter-fitting 'splined elements having a slight amount of play between thein to permit small movement su-flicient to accommodate slight differences in alignment between the stator sleeve 6, which is" carried on the rotor bearing sleeve.

31, and the ratchet'element 56, which rotates on an inward annular huh projectidn 61 of stationary plate .53. V

While, as previously described, the driven shaft44 is supported upon the stationary plate 53 a suitable anti-friction bearing 55 (which may. be eithero'f the ball oi roller type), such hearing would not provide aproper seal to prevent the escape of fluid from the transmission. The necessary seal is provided by a second floating diaphragm packing device 63 similar to the packing device 43 interposed between the driving rotor and astationary member fastened to casing 51,."

Two seals are thus provided, one between the driving and-stationary parts, the other between the driven and stationary parts. ,-Any good packing device may be used at these points. However, the floating diaphragm type, which is the subject of my co-pending United States applicatinSeria1 No. 688,247, hereinbefore referred to, is particularly adapted to the purpose. 1 i

The inner elements'of my packing device comprise two annular retaining rings 64, between which is firmly clamped a spacing ring of lesser diameter. A floating annular ring 66 runs freely in the space between the retaining rings 64:, the ring 66 virtuallyfloating because of the fact that it is circumferentially supported by a comparatively fiexi ble diaphragm 67 The floating ring 66 and diaphragm 67 are rigidly fastened together, the diaphragm preferably being clamped between the two halves of such ring. The diaphragm and floatingring form the stationary part of the packing device, and the diaphragm is clamped around itsouter edges against a spacing ring 68, which holds thebea'ring 55 in place; and the inwardly projecting flange of a threaded-retaining ring 69, which screws on to an annularextension .70 formed integr ally with supporting plate 53. It will be )bserved that the annular extension 70 on supporting plate 53 provides a seat forthe outer.

member of the antidriction bearing 55.

If, as in the present instance, it is desired toiinc'orporate a friction brake to act on the transmission shaft, a brake drum having a central hub portion 7 6' may be keyed to the driven shaft 4, as shown in Fig.1, the drum being held rigidly in place against axial displacement by a large nut 77 threaded directly on the drivenshaft 4c. In this construction the shaft 4 is provided with a shoulder or flange portion 4 7 8, against which the inner ring of the anti-friction bearing 55 rests. The inner member of the floating packing device, 63 and the end wall of brake drum 75, are, like the inner ring of bearing 55, so disposed as to be rigidly clamped together between flange 78 and the aforesaid nut 77. The brake drum 75, floatingpacking device 63 and antifriction bearing 55 are thus centrally clamped together in such fashion as to provide a fluidtight joint between such elementsand the driven shaft 4. I

The transmission is preferably designed so as to insure access of the fluid transmission medium toall of its moving partswhereby adequate lubrication is insured if asuitable lubricating oil is used as the power tfansmitting medium. It will, however, be understood that theonly which has access to the transmission bearings'and'packing devices 43 and 63, and also tb the annularchamber 50 surrounding the pumps,-isthe idle fluid I which'is not ordinarily subject to any fluid pressure whateverother than that'representi ed bythe small hydrostatic pressure duelto the elevation of an oil reservoir which is indi-5 j reet communicatlon with the interior of the transmission througha pipe 80. In a trans mission so des1gned there,1s obviously no real difficulty in preventing-the'escape of fluid, be- I cause at none ofthe points where leakage would. be likely to occuris there'present any appreciable fluid pressure. Very large fluid pressures are, of course, developed between the co-operating pressure chambers of the two pumps A and B, the degree of pressure varying with the torque load,but this high pressure is confined to the working chambers of the pumps and the short pr'essurechannels 23 connecting these chambers together.

.Sjmall bores communicating with the pressure chambers of the pumps admit this driving fluid pressure to certain chambers of the auto matic control mechanism, as will hereinafter be fully set forth, but the fluid underpressu're is confined in the various control chambers so that, as above stated, for allpractical purposes. as faras the problem of leakage is concerned, the fluid under pressure is confined to the working chambers of 'the'pumps and it never reaches the bearings. Thepassages which provide forthe distribution of idle fluid to all parts of the transmission for lubricatihg purposes will now be briefly described. The details. are clearly shown in Fig. 1; It will be seen that between all the relatively moving parts of the transmission which are not required to" bear against one another, space has been provided for the free flow of fluid; A series of channels are easily traceable in the figure from the pipe 80 communicating with the reservoir (n'ot shown) to both of the floating packing devices 43 and 63, andialso to the interior of the long sleeve bearings 6 and 31 surrounding the driven shaft 4. .These bearings receive fluid midway between theirends through ducts 81 communicating with a central bore82 in the driven shaft, which bore, at the right hand must be taken to eliiz inate air from the various chambersand passages, which is accomplished by venting the chambers to the atmosphere, suitable screw plugs being provided for this purpose at various points, one such plug 84 being shown in dotted lines at the top of the driving rotor in Fig. 1.

An important feature of novelty of the present invention resides in a means formechanically connecting the stator of the receiving pump or motor B with the driving rotor- 1, whereby the said pump is rendered inoperative when its capacity to receive fluid is not Wanted.

This is the case when the transmission is to operate in direct drive. As hereinbet'ore set forth, if no relative motion can take place between the vanes 9 carried by the stator, and abutments 13 carried by the driving rotor, the receiving pump B- has, no

.capaeity whatever to receive fluid from the delivery pump A, and since the only path of escape for fluid'from the pressure chambers of the delivery pump is through the receiving of the driven rotor.

drive there will be no mechanical losses whatever due to the friction of working parts orresistance'to fluid flow.

One construction for clutching the releasable stator 5 to the driving rotor 1 is illustratedin Fig. 1'.- However, thepreferred embodiment of this portion of the mechanism is illustrated in the enlarged fragmentary View shown in Fig; 9. The form in Fig. 1 will be first described.

The clutch may, of course,be operated in any suitable manner and my invention is not limited to the operating mechanism herein I described- In the preferred embodiment the clutch is automatically set and released in. ac-

cordance with the operating conditions to which the transmission is subjected, the clutch being directly actuated by fluid. pressure which is under the control ofautomatic valve devices,'which will hereinafter be described.

II-n Figure 1 the clutch is shown as comprising a single friction disk 90 which is splined to the hub portion 6 of the releasable stator The arrangementof splines 91 is also shown in Figure 4. The disk 90 is therebyrigidly held against .rotation with respect to the stator but is free to slide axially over a slight distance to permit accommodation between it and the friction elements 93 and 94',

- with which it co-operates. I The element 93 is of the recess 95.

an integral part of the drivingrotor 1, and the element 9% is a fiat ring which is situatedin an annular recess 95 in the member 33', which latter is also a part of the driving rotor. The friction element94 is actually: an annular piston, suitable packing being provided in grooves 96 .to make it slide in substantially'fluid-tight contact with the walls When fluid pressure is admitted to the:

chamber 95 on the right hand face bf piston 94, such piston moves to the left, and since If the annularlpiston 94 be relieved of fluid pressure .on its right hand face, a plurality of return springs 97' insure-the disengagement of the clutch by forcing the piston back .into its annular recess 95. a

The preferred construction of the fluidactuatedfriction clutching device is shown in Fig. 9. The elements in this figure which are referred to by numbers having prime marks after them, indicate members whose function corresponds to elements similarly numbered but withoutthe prime marks in Fig. 1. Thus, the apron 37' corresponds to apron 37 though in Fig. 9 it is shown as a somewhat heavier construction, and the clutch housing disk 36 corresponds to the clutch housing disk 36, etc. In Fig. 9 the friction .disk 99 of the clutch is slidably splined on the hub 6' of stator 5', as in the embodiment previously described.' The function of the clutch disk 90' is also the same, i, e., to couple the stator to the driving rotor. The clutch disk is forced into contact with friction surface 93' by means of a fluid-actuated element comprising an annular plate-like memher 100 having acentrally formed circular flange 101 fitting loosely into' the annular recess within the plate,33 The fluid-actuated member 100 is coupled by means of splines 102, to the driving rotor so that it rotates therewith, but is free to moveaxially.

In this embodiment the fluid does'not" directly act upon disk 100 (corresponding to annular piston 94 in the embodiment shown in Fig. 1) but instead acts on a fiexible d-iapliragm 103, which may be made of flexible sheet metal, leather or other suitable material. The movement required between the parts to effect the clutching and uncoupling of the co operating clutch elements is so slight that the flexible diaphragm is not unduly stressed orsubject to wear. The clutch disk 90' isprovided with a plurality of boTres 104 which:

permit idle fluid to pass from one face to the other, so that the disk will not tend to adhere to the surfaces with which it; co-0perates after the actuating disk 100 has been relieved from the fluid pressure. o The automatic clutch-control mechanism tion with either the clutch device shown in V Fig. 1- or that shown in Fig. 9. The mecha- :nism comprises two valves, C andD respectively. ,The valve we willcall the master valve, and'the valve D the pilot valve.' The function of the master valve 0 is to connect the annular space to the right of the clutchactuating members (.94 in Fig. 1, 100 in Fig.

9) with the pressure side of the pumping system or with the idle fluid side, in the former case to apply the clutch, and in the latter to release it. ,Thefunc'tion of the pilot valve D' is to relieve the master valve of fluid pres-. sure at speeds below a predetermined number of R. P. M. Until such. speeds are reached, the master valve is under the control of the pilot valve, and under no circumstances can fluid pressure act on the clutch to produce direct drive until this criticals eed of the pilot valve has been exceeded. 'l he master 'valve is designed to be respon- I sive'to the opposing 'actionsof centrifugal inghollo'w stem Z, the diameter of 'whichi-isJ force and fluid pressure, while the pilot valve is sensitive only to centrifugal forceagainst the actlon of a spring. Above apredetermined speed of the driving rotor 1, in which both valves are mounted, the pilot valve D will occupy the position shown in' Figs. ;and 7, and below this predetermined speed the. pilot valve will occupy the position shown in ;Fig. 6 in dotted'lines.

Fluid pressure from the working chambers of the vane pumps is admitted tothe pilotvalve bore at through a port e,.and the valve bore is in communication with the idle fluid side of the transmission through port The pilot valve proper comprises a p1ston g, which, toward its inner end, is cut away to provide an annular recess h. This recess is v of the.valve,-and thus it willb'e sufiiciently wide so that when the valve piston g is in the position shown in dotted lines Fig. 6 (its inner position), the port i, which connects the pilot valve with the master valve G, will c'ommunicatewith the idle fluid port f 'through said annular r'ecess h. The said port 71 between the two. valves C and D, when-thevalve is in the position shown in Fig. 5 (its outer position), will communicate with pressure port a through the said annular recess h. The piston 9 slides freely in its bore so that 1 it is responsive to the action of centrifugal force, which tends to move it outward against the tension of a coiled spring The'master valve compr ses a piston hav preferably abouttwo-thirds that of the piston 'k. Saidpiston slides within a bore" which has at its inner end abore n of reduced diameter in which the hollow stepo'l of the piston nicelyzfits. The tgler'ance between the clutch-actuating device, which may be either the ring 94 in 4 plate 103 and 100 respectively,-in Fig. 9.

The hollow stem Z of the master valve is surrounded by a spring 12 which tends to maintain the valve'in its outer radial position. 4 The port or passage 2' connectingv the two valve chambers, as-shown in Figs. 5 and 6, isinclined so that the lower part of the pilot valve chamber communicates with the upper part of the master valve and at a point where ig. 1 or thediaphragm and the bore me in'whioh the valve piston slides is somewhat enlarged so as to provide a "space 9 around the valve head is. The outer end the. position shown in Fig. 5, the ports '8 com-- which receives muni'cate' with the space 5, fluid from the pilot valve "through passage surround the valvehead and also to.

2'. "When the valve C is in the position shown in Fig. 6, ports 8 have moved down into the bore m where they communicate with a vent port t connected to the idle fluid spaceof the transmission through a passage 10. At the same time, communication between the passa e z" and the interior of the valve stem is out o ports 8' no longer registering with the space g, which receives uid through said passage. I In either position of the valve the port 0 always communicates with the interior een that when the master valve is in its inner lfiositi-on 6) the clutch-actuating device will be placed in communication through the hollow valve stem with vent assa e tand relieved of fluid pressure, and w en t e master .valve is in its outer position (Fig. 5), the clutch-actuating device will be connected through the valve stem with passage z, through which fluid under pressure will be'delivered to cause the clutch to engage, providing, of course, that the transmission is rotating at a suflicient speed to causethe pilot valve D to occupy itsouter position, as shown in Figs. 5'and 7 According to the preferred embodiment of the present invention, the pilot valve D is responsive only to variations in speed. Below anwpredetermined-number of R. P. M. for

which the 'valve'l) is designed, it will occupy its inner position ('do'ttedllines Fig. 6) and in this position'it will prevent'themaster working parts of botltvalves is made as small valve C from moving to its innerposition' bebeing sufficient, however, to insure free work-1 ing of theparts; Atthe inner end of the small'bo're n of the masteryalve'O, a port 0 connects with the space to the right of the" cause no fluid pr ssure-willbe admitted to the space 9, an consequently there will be nothingto oppose the action oi centrifugal force and spring p, both of which tehdto keep the master valvein-its outerposition However, under these circumstances since master valve, the friction clutch will not be engaged as would otherwise be the case when the master valve is subjected to pressure in its outer position. This situation results in a reduced speed drive or free engine, as the case may be, as willhereinafter 'be particularly in the operation of the master valve C, the

set forth.

With the pilot valve D'in its outer position (Fig. 5), the master valve 0 mayv occupy either its outer or inner position, because, with the pilot valve in the position stated, the

master valve will'be exposed to fluid pres-i sure from the working chambers of the pumps through ports and passages 6, hand i tending tomove such valve inwardly, and also to the action of centrifugal force tending to move thevalve outwardly. The position of the master valve is thus determined bythe simultaneous and opposing'actionsof cen-itrifugal force and fluid pressure, the spring go further augmenting the action of centrifugalforce in opposition to fluid pressure, which tends to move the' valve inwards. When the pilot/valve. is in its outer position the master-valve will therefore determinewhether the friction clutch be set for direct drive or released for a reduced speed, in ac cordance with a force which is the resultant of the fluid pressureacting on the valve against the action of centrifugal force and spring p.

Furthermore, since the fluid pressure 1s a function of the load placed upon the transmis sion, it will be'apparent'that' as the load on the transmission increases, 'therewill be an creasing tendency for the fluid pressure to v move the master valve to a position correovercome the combinedeifectof cen'tri fugal sponding to a' reduced speed drive. If the. eed of the prime mover remains constant,'

s the increasing fluid pressure ,will eventually force and spring 17 and set fthe 'transmission speed of the prime 'moverbe. increased, thefor a reduced speed. Assumingnow that the transmissionis so set, the master valv'e C being in its inner position as shown in Fig. 6, and the load remaining constant, if now the driving rotor in which the valvesare mounted will increase the action-of centrifugal-force upon the master valve, and there .will comea point where the combined action of centrifugal force and spring 2 will be suflicient ing'as to which of the forces due to engine speed or load torque, preponderatesg, At high engine speed a relatively heavy load will be required to set the transmission forareduced speed drive, and at low engine speed a relatively small'load will set the transmission for a reduced speed. drive. The control eflected by theautomatic valves, therefore, corresponds to the best practice in manual gear shifting.

To avoid fluttermgand other irregularities valve is constructed so that its elfective pressure area against which fluid may act to move the valve inwards, is very much greater when the valve is in'its inner position than whenthevalve is in the outer position. When the valve is in the position shown in Fig. 5,-its effective pressure area is representedby the difference in cross-sectional'area between the bore/mg and the bore it, since fluid pressure enters the interior of the valve and over the area of bore n acts outwardly in opposition to the pressure on the head of piston is; When the valve is in the'inner position, however ports 8, which admit pressure to the valve in-. terior, are no longer open, and in consequence, fluid acts upon the valve head k'with full effect, there being no opposing fluid pressure whatever. The result of this design is to keep the valve in its inner position once it has been moved to such position, until the'fluid' pressure which brought about such movement and set the transmission for reduced speed drive shall have decreased materially below that pressure which effected the movement; If this construction is not employed, the valvev would tend to move outwardly the moment the pressure fell below that required to shiftthe valve inwardly, and under certain conditions the transmission would then be shifted from high or direct drive into reduced speed drive andback again to direct at very frequent intervals and without permitting a sufficiently long-operation in reduced speed to obtain the benefits of acceleration.

For example, with the modern six cylinder car it is possible to slow down in direct drive to'five miles an hour, and even on a fairly steep grade gradually accelerate up to any speedwithin the capacity of'the motor, butthe time required to attain any given speed will'be very much longer than if intermediate driving-gratios were employed when the car speed is low to permit the engine toturn over at ,'a. speed where it is developing something like its maximum horse power. The design of the master valve G is calculated, within practical limits, to bring about this desirable result by keeping the transmission set in reduced speed as longas the car acceleration will be improved by reduced speed operation.- 7 Havin nqwdescribed the automatic con:

trol mec an smuwhereby direct and inter mediate speed drives are obtained, we .will now describe the automatic mechanism which provides the condition of free engine and a variable slipping clutch effect between free engine and the aforesaid intermediate speed.

The mechanis ill air shifting from direct drive to intermediate speed or vice versa comprises an automatic hydraulically-operated friction clutch. The control. now tobe described comprises one.or more -automatically-actuated valves whiclycontrol by-pass portso, through which the working or pressure chambers of therp umps are by-passed to the idle fluid side of the-transmissionr It is obvius that if such'by-pass ports are opened, no appreciable driving effect will be produced upon the driven rotor 3and driven shaft'i byrotziting the driving rotor 1. A pumpingfefiect will tween them, through the by-pass ports and back through chamber 34? and ports 34: in plate 32 into the idle fiuidspace surrounding the pumps. In'the embodiment of the invention illustrated'in Figs. '1 and 8, two of these free-engine or idling valves-are shown,

but sincethey are of identical-construction,

only one will be particularly described. 1

The valve in its entirety is referred to by the letter E and comprises a bore 'w, having 4 ports n and w, and within which slides a pise ton y havingtowards itsouter end an annular recess y. When the valve 1s m the inner position (Fig. 1), the annular recess provides a communication between the ports 0 and :12 whereby fluid flows freely from the working chambers of the pump outward through ports w. into the idle fluid spaces34 surrounding the valve mechanism, and which are in open nommunication with the other idle' fluid ,spaces of the transmission through passages 34: as hereinbefore set forth. When the valve'is in itsouter position (Fig. 8-), port '0.

- is olosed,locking the fluid within the working chambers of the two pumps where it may act either to produce an intermediate speed drive or direct drive in accordance with the control of the previously describied valves 0 and D acting on' the friction clutch. Be-

tween thesetwo extreme positions the valve E may assume an'infinite number of intermediate positions by which varying degrees This speed is arbitrarily chosen'as a suitable idling speed for the automobile engine, but obviously, if it were desired to have the engine idle at higher speeds, it would simply require a spring of slightly greater tension to be used or an adjustment provided for the present spring. "Below the speed of 250 R. P. M.,'

the valve being wide open, no appreciable torque will be transmitted from the driving to the driven parts of the transmission. If now the engine throttle be gradually opened, thereby increasing the speed of the driving rotor 1 in which the valves E are mounted, the ports 2) will be gradually closed by the outward move ment of the valve against the resistance of the spri under the increasing-centrifugal force. "iihis will result in a very smooth and gradual application of power to the load, the free by-passing of fluid from the pressure chambers of the pumps being more and more restricted with increasing speed, thereby building uprhigher pressures within the pumps, which, acting on the vanes of the driven rotor, smoothly'accelerate the load up 7 to the intermediate speed of the transmission, which is determined by the relative capacities of the delivery pump A and receiving pump ormotorB. Y It will be observed that as soon as the valves E commence to restrict the by-pass ports and thereby create pressure within the pumping system, the stator will tend to rotate backwardly, but such motionbeing checked by the ratchet deviceS, a booster effect will be had in the motor B. This action will become more effective with increasing pressure as the valves are closed. In consequence of this, the efdciency of the transmission is materially in,-

creased over the range from zeroup to intere produced solely by t-he slipping clutch action of a by-pass valve without the-booster efl'ect I of the motor. Ordinarily the power loss in aslipping clutch is directly proportional to the diflference in speeds between the driving and drivenelements, but in the present con-V mediatespeed than if the acceleration werestructionthis will only be true at the instant of starting, and actually over the entire range between. zero and intermediate speed the of slip are obtained running from 100% slip losseswill be reduced practically one-half-be-' when theiralve is open, to no slip when th valve is closed. a Y

The position of the valve E is automatically determined bythe speed of the driving rotor.

The valve may serve as its own centrifugally governing mass, as illustrated, the outward coiled spring- 2, which is retained inplace by to the mass of the piston valveso that up to aformed cylindrical lugs 112, said lugsenga'gv a guide rod' 2', the guide and spring fitting within .a. central bore 2 formed in the. valve piston. The spring 2 is designed with respect speedof 250 R. P. M. the valve will be recause of the booster action in the motor.

The two valves E controlling ports u (one foreach ofthe pressure ohambersrof the de livery pump, which is of the duplex type, i.' e.,

the pump has two abutments) are connectedtogether by. means which will now be described, so that their movements, while in g V opposite directions, will be equal and synchronous. Within thebore z'fof each ofthe valve pistons y", one end of an offset arm '110 is fastened by means ofa pin 111. On the other end ofeach'of the offset-arms 110, are

ing diametrically opposite slots 113 in a ring i the. driving rotor and freely rotatablethereon.

While the valves, if perfectly adjusted, would tend to move synchronously without any connection between them, the linkage described is preferably employed to insure their synchronous operations; Pins 115 set in the wall of the valve bores engage slots 116- tomeans a perfect equalization of fiuid pres sure will'be obtained,.and practically all-unbalanced forces between the variousrotating parts of the transmission eliminated; A convenient connection between the pressure chambers is provided by conduits 120 which communicate with the annular recesses '0 surrounding-the valve bores "w, the pressure ports 0 at all times communicating with. said recesses regardless of the position of the, valves y (Figs. 1 and 8). V

The pressure-balancing channels 120 are preferably formed in the main casting of the end plate 32, as are also the housings for the .two valves E. The Walls of the valve housings and pressure-balancing channels need not be of great thickness, as none ofthese parts are. subjected -to mechanical stress and consequently need only be sufiiciently strong to withstand the interior fluid pressure.

Webs 121 may be cast integrally with the end.

plate 32 and the valve housings to support and brace the latter,-and also to reinforce the 7 cover plate 34: which completely-encloses the 7 idling valve mechanism. s

V of the fluid on its-way from the delivery pump A to the receiving pump B. So smooth and In Fig. '11 there is shown a development of the working chambers of the pumps. The reverse curves X indicated in dotted lines between the two pumps show the actual path direct a passage between the two pumps is rendered possible bythe elimination of any valves between-them, and, as hereinbefore the same-radial distance from the axis of the.

' pumps need notoe greater than one-inch, andi may, by proper design and use'of correct ma set forth, has greatly decreased the losses which have heretofore been occasioned by the resistance to theflow of fluid through tortuous passages and valve mechanisms. The

pressure chambers-of the two pumps are at transmission, and consequently theactual length of 'tlie'passage connecting the two terlals the-construction of the device,bc reduced to evenless than this} A feature wbichmat erially contributes to the high efli ciency of the present transmission is the curved and angularly-disposed faces 'Z of the abutments 13 and 22, by means ofwhich the fluid, instead of being abruptly'diverted at co-pending By this sion employing only two pumps.

pump chamhers',-.is gradually accelerated by the smooth-curves Z, so that .it leaves rthe pump A- and enters theireceiving' pump B smoothly and without turbulence; The form and arrangement of the abutments 13 and 7 22 by which this smooth flow of fluid out of the delivery pump and into the receiving pump is obtained, is fully descrihed in my United States applicationserial Certain of the features embodied in this invention are applicable to a wide variety of hydraulic transmission apparatus, 'andit is to be understood that the. transmission hereinbefore described ismerely chosen as illustrative of one application ofthe features of the invention to a hydraulic transmission of the differential pumping type. The inven-' tion obviously is not limited to a transmis rangement of driving and driven parts is not restricted to any of the forms illustrated. In

The ar- 8 the hydraulic transmission art-a number of differential pumping devices are well known which are not herein particularly referred to, butwhich' obviously are well adapted to em-' ploy the automatic transmission. ratio controlling devices hereinbe'fore described. A

well-known alternative form for the difierential pumping type of transmission shownfi'n' '9.

Figfilamounts to the' same construction turned inside out; that is to say, the rotor which is common tof-the two pumps A and B is an internal rotor,,while' the statorand sec- 0nd rotor are formed externally tosaid com i mon'rotor. In this latter construction the powerv may be applied either to the common internal rotor or to the second external rotor co-operating therewith, resulting in trans missions having the characteristics of what I have termed the normal and the inverted drives respectively.

' The-invention may be otherwise variously modified and embodied without departing I from the spirit thereof, as set forthinvthefollowing claims.

lVhatIclaitn is: V J 1. 1A" change-speed transmission comprising driving and driven elements,'hydraulic' speed-varying pumping means including a releasablestator, and a clutch between said stator and one of said elements. Q

2. A. change-speed transmission con prising driving anddriven elements, hydraulic 'ing driving and driven elementshydraulic speed-varying pumping meansincluding a releasable stator, and a friction clutch bed-varying pumpmg means including .a ,15

rightang lesio its motion v in the delivery tween said stator and one of said elements, 13

and hydraulic means for actuatingsaid Clutch. I

4. A change-speed transmission comprising driving and driven elements,'hydraulic speed-Varying pumping means including a releasable stator, a-clutch between said stator and one of said elements, and means actuated.

by centrifugal force and fluid pressure for controlling the operation of said clutch.

5. A change-speed transmission comprising driving and driven elements, hydraulic speed-varying pumping means including a releasable stator, a clutch between said stator and one of said elements, andcentrifugally= operatedmeans for controlling the clutch; I

6. A change-speed transmission compris-' and driven elements, hydraulic ing drivin speed-varying pumping means including a releasable stator, a clutch between said stator and one of said elements, and pressure-operated means responding to load torque for operating the clutch. c

7. A change-speed transmission comprising-driving and driven elements, hydraulic speed-vary ng pumping means including a releasable stator, a clutch between said stator and one of saidelements, hydraulic means for actuating said clutch, and a val-ve'for con-. trolling the said clutch-actuating means responding oppositely to centrifugal force and fluid pressure 8. A change-speed transmission comprising driving and driven elements, hydraulic speed-Varying pumping means including a releasable stator, a clutch-between said stator I and one of said elements,'hydraulic means for actuatingsaid' clutch and automatic means for controlling said clutch-actuating means,

said automatic means comprisinga master valve and a pilot valve,t he latter responding to centrifugal force and controlling the admission of pressure to the master valve.

9. A change-speed transmission comprising drivin and driven elements, hydraulic speedsvarylng pumping means including, a

releasable stator, a clutch between said stator.

and one of said elements, said clutch-comprismg a disk "connecting with the stator and coacting with a friction part carried by one of ,the said elements, and a pressure-actuated 7 part to force them together.

10. A change-speed transmission comprising driving and driven elements, hydraullc speed-varying pumping means including a releasable stator, a clutch between said stator and one of said elements, and a centrifugallyoperated by-pass valvefor starting andstop- P A change-speedtransmission comprising a driving element, a driven element, and a releasable stator, two pumps,- a' fluid circuit connectingsaid pumps, one of said pumps being actuated by the difference in speed bethe other of said pumps beingactuated byjthe ing driving and driven elements, hydraulic tween the said driving and driven elements,

' speed-varying pumping means including a releasable stator, aclutch between said stator difi'ere'nce in speed betweenoneof said 1316- ments and said releasable stator, and mechanical clutching means between said stator'and one of saidelements. V v v 12. A change-speed transmission comprising a drivingelement, a drivenelerr'rent, and J a releasable 'stator, two pumps, a fluid circuit connecting said pumps, one of said pumps being actuated by the difference in speed between the said driving and driven elements, the other of said pumps being actuated by the difference in speed between one of said 'elements and said releasable stator, a mechanical clutch between said stator and one of said elements, and hydraulic actuating means for said clutch. v 13. A change-speed transmission comprising drivin and driven elements, hydraulic speed-varymg pumping means including a releasable stator, a clutch between saidstator and one of said elements, and torque-resp'on: sive means adapted to actuate said clutch. 14. A change-speed transmission compris; ing driving and driven elements, hydraulic speed-varying pumping; means including a releasable stator, a clutch between said stator and one of said elements, and speed-responsive means adapted to actuate said clutch. A 15. A change-speed-transmission comprising driving and driven elements, hydraulic 5 H speed-varying pumping means including a res leasable stator, a clutch between said'stator. and one of said. elements, andmeans simul-' taneously andoppositely responsive tothe speed of one of said elements and the torque load for' actuating said clutch. j g

.16. A change-speed transmission comprising driving and driven elements, hydraulic 1 05 f and one of saidelements, torque-responsive .means adapted to actuate saidclutchi, said means" requiring a materially higher. load torque'to initiate itsmovementthan i s' required tomaintain said means in the posi- ,i tion' to which it is moved by inqreasing.

17. A change-speed transmission comprisr ing driyingand driven elements,. hydraulic v speed-varying'pumping means including a releasable stator; 21, hydraulically-actuated clutch between said stator andoneof said elements adapted,'.when engaged, to rotate th stator and thereby hydraulically couple the; elements together for directdrive, r '18. Achange-speed'transmission compri ing driving and driven. elements, hydraulic speed-varying pumping means including {a releasable stator; a hydraulically-actuated5;; clutch between said stator and-one ofisaid ele- 2 j ments, and a valve oppositely responsive to fluid pressure and centrifugal force for controllin said clutchrf d 19. change-speed transmission comprisspeed-yarying pumping means including-a releasable stator, a' hydraulically-actuated clutch between said stator and one of said elements, and a valve responsive to fluid pressure, said valve having a greater eifective pressure area in the position to which it is moved byincreasing fluid pressure than it has 7 in the position frbm whichit is so moved.

clutch between said stator and said driving @element, and a' valve oppositely-responsive to fluid pressure and the speed of the said driving element for controlling said clutch.

, 23. A change-speed transmission compris-' ing driving and driven elements, hydraulic speed-varying pumping means including a releasable stator, a ratchetdevice adapted to check the backward rotation of said stator but to permit free forward rotation thereof, and a clutch between said stator and one of said elements adapted by its mechanical control of said pumping means to hydraulically couple the elements together.

2,4. A change-speed transmission compris- "ing driving and driven elements, hydraulic speed-varylng pumping means including areleasable stator," a ratchet device adapted to check the backward rotation of said stator but to permit iree forward rotation thereof,

- and a fluid-actuated clutch between said stator 4 and the said driving elem'ent.

25. A change-speedtransmission comprising a driving. element, a driven element, and a releasable stator, two pumps, a fluid eircpit connecting. said pumps, one of said pumpsbeing actuated by the difference in speed between the said driving and driven elements,- the other of said pumps being actuated by the difi'erence in speed between said driving e lement and said releasable stator, and a clutch between said stator and said driving element.

' 26,, A change-speed transmission comprisinga driving element, a driven element, and 'a vreleasable. stator, two pumps, a fluid clrcultfl connecting said pumps, one of said pumps being actuated by the difference in speed between. the said driving and driven elements, the other of said pumps being actuated by the difference in speed between said driving element and said releasable stator, and ahydraulically-actuated friction clutch between said stator and said driving element.

27.- A change-speed transmission comprlsmga drivlng element, a driven element, and

a releasable'stator, two pumps, a fluid circuit connecting said pumps, one of said pumps being actuated by the difference in speed between the said driving and driven elements,

the other of said pumpsbeing actuated by the difference in speed between said driving element and said releasable stator, a fluid pressure actuated clutch between said stator and said driv ng element, anau-tomatic control valve carried by said driving element, said valve being oppositely-responsive to fluid pressure and centrifugal force and adaptedto control said clutch.

28. A change-speed transmission compris ing a driving rotor, a driven rotor, and a releasable stator, a delivery pump actuated by,

the difference in speed between said driving and driven rotors, a receiving pump actuated by the difference in speed between said driving rotor and said stator, a hydraulically-actuated clutch adapted to connect said driving rotor and said stator'together, and a valve mounted in said driving hydraulically control said clutch. V

29. change-speed transmission accord ing tojcl aim 28, further characterized in that the driving rotor comprises a casing surrounding said driven rotor and said stator; 30. A change-speed transmission according to claim 28, further characterized by the inclusion of a by-pass valve adapted td permit a variable hydraulic slip between the said rotor adapted t driving and driven rotors whereby operating conditions may be obtained varying from free engine to the reduced'speed drive determined by the relative capacities of the said pumps. 31. A change-speed transmission according to claim 28,;furtl 1er characterized by the SVEN GUSTAF WINGQUIST. 

